Abby Andersen, 4, enjoys an ice cream cone, on a hot day a the Denver Zoo, Denver Zoo, April 27, 2018 in Denver.

RJ Sangosti, The Denver Post

Denver Zoo with interim CEO Denny O'Malley stand in the Toyota Elephant Passage at the zoo on April 27, 2018 in Denver. The Denver Zoo hopes to have a new CEO in place by June 1, but in the meantime itÕs restructuring its board and bringing in more fundraisers and community members.

RJ Sangosti, The Denver Post

Denver Zoo's interim CEO Denny O'Malley, left, and Brian Aucone, Senior Vice President for Animal Sciences, talk about future activities at the zoo, April 27, 2018 in Denver. The Denver Zoo hopes to have a new CEO in place by June 1, but in the meantime itÕs restructuring its board and bringing in more fundraisers and community members.

RJ Sangosti, The Denver Post

Denver Zoo with interim CEO Denny O'Malley stand in an exhibit that is part of the Toyota Elephant Passage at the Denver Zoo on April 27, 2018 in Denver. The Denver Zoo hopes to have a new CEO in place by June 1, but in the meantime it’s restructuring its board and bringing in more fundraisers and community members.

In the middle of a busy weekday at the Denver Zoo, Denny O’Malley squats to pick up the discarded crust of a grilled cheese sandwich.

A wave of people — kids, parents and grandparents streaming toward him from the Predator Ridge exhibit, which on this day features African lions and wild dogs — parts around O’Malley as he tosses the crust into a trash can.

It’s not exactly his job. As the zoo’s interim CEO, O’Malley is only a temporary steward of this 121-year-old city within a city that costs $100,000 per day to run and houses about 4,000 animals representing 600 species.

But before the Denver Zoological Foundation can hire a new CEO to replace ex-president Shannon Block — who left abruptly in June, after the zoo’s high-profile spat with the city auditor — O’Malley needs to attend to the fine details of this nonprofit institution that last year welcomed a record 2.2 million visitors and bills itself as Colorado’s most-visited cultural destination.

Even if he must attend to the grilled-cheese crusts.

“On real busy days, this can be a tough place,” said O’Malley, a former zoo board chairman who was previously president and CEO of Craig Hospital. “Parking can be tough, and if we continue to see a spike in our attendance, there’s some concern about that. But there’s many days when that’s not a concern, because there’s unused capacity here, too.”

Photo provided by the Denver Zoo

The Denver Zoo welcomed the birth of two, male red panda cubs on Aug. 27, 2017. The brothers, who don't have names yet, have been quietly spending time behind the scenes with their mother, Faith, in a nest box. They will be visible to the public in a few weeks when they're ready to join their father, Hamlet, in the Zoo's red panda enclosure.

The Denver Zoo announces the birth of a western lowland female gorilla, named Whimsie Adepa . She was born to mother Tinga (TIN-gah), and father, Jim, just before midnight on Feb. 25, 2016. She is the first birth of her species at the Zoo in 11 years and the fifth ever in the Zoo's history. The second part of her name, Adepa, translates to "good thing" in the Akan (AH-khan) language of Ghana. Guests can see her now at the Zoo's Great Apes building.

Kathryn Scott, The Denver Post

The Denver Zoo announces the birth of a western lowland female gorilla, named Whimsie Adepa . She was born to mother Tinga (TIN-gah), and father, Jim, just before midnight on Feb. 25, 2016. She is the first birth of her species at the Zoo in 11 years and the fifth ever in the Zoo's history. The second part of her name, Adepa, translates to "good thing" in the Akan (AH-khan) language of Ghana. Guests can see her now at the Zoo's Great Apes building.

Provided by the Denver Zoo

The unnamed sarus chick hatched on Aug. 17, weighing .291 pounds.

Provided by the Denver Zoo

The unnamed sarus chick hatched on Aug. 17, weighing .291 pounds.

Provided by Denver Zoo

The female kea chick, named Scarlet, hatched at the Denver Zoo on February 8.

Denver Zoo

Umi, an endangered Malayan tapir, was born May 6, 2017 at the Denver Zoo.

Photo provided by Denver Zoo

Baby giraffe Dobby was born at the Denver Zoo on Feb. 28, 2017.

Provided by the Denver Zoo

Denver Zoo's fishing cat cub named Miso-Chi was born on January 25., 2017.

Dave Parsons, Denver Zoo

In this Aug. 2009 handout photograph provided by The Denver Zoo, emperor tamarin monkey twins Lara and Lucy look on from their home in the zoo's nursery. The twins are being cared for by zookeepers after they were orphaned on July 30 when their mother died from cancer, three weeks after giving birth to the pair.

Photo provided by Denver Zoo

The Denver Zoo is celebrating the birth of an endangered Przewalski's (sheh-VAL-skeeÕs) horse foal, born the morning of Oct. 29. The male, unnamed foal, was born to mother, Yisun, and father, Bataar. This is only the second birth of this species at Denver Zoo since 1991. The foal is quietly exploring its yard under the watchful eye of its mother, but guests can see them both from the Zoo's main pathway now.

Photo provided by Denver Zoo

Denver Zoo said a baby zebra was born 2015 in front of visitors. Sean Andersen-Vie says the zoo has not yet named the new animal.

Photo provided by Denver Zoo

City Park Zoo- Denver Zoo Polar Bear Cub "Cranbeary" Made his first public debut! early Wednesday morning. Cranbeary (female) was born to Voda(female) and Kavek (male) on Wednesday, Nov. 21,2001, the evening before Thanksgiving, the baby cub weigh 22 pounds and has been growing stronger each day. Photo of Cranbeary who came up to the glass and pose for the press.

Cyrus McCrimmon, The Denver Post

The Denver Zoo is celebrating the arrival of a new baby hippopotamus who was born December 11, 2002. He is named Mahali (Swahili for spot, and he has a spot on one of his back legs) and was sandwiched between a hay eating dad "Bertie" (left) and his mother Samantha. Bertie is now a 46 year old father and Mahali is Samantha's 15th baby. The hippos are indoors in the Pachyderm building.

Glenn Asakawa, The Denver Post

Betty, a bactrian camel, nuzzles her newborn, unnamed female baby, at the Denver Zoo April 2, 2003. The baby was born around 8:30 am and is healthy and bonding well with her mother according to zoo officials.

A five-day old giraffe the Denver Zoo has named Kala huddled in the corner under the protective eye of her mother Masika May 27, 2003. The baby who stands 5'10 and weighs 158 pounds, will likely be on public display Thursday. Kala is the second calf born to Masika and Dikembe the zoo's male giraffe. Giraffes are the world's tallest land mammal and can grow up to 17 feet tall. Denver Post photo by Karl Gehring. (5-27-03)

Kathryn Scott, The Denver Post

A brand new baby Western lowland Gorilla was born on May 2, 2004, at the Denver Zoo and has been transferred to the zoo's nursery to be hand-raised by zookeepers. The female baby Gorilla does not yet have a name, and the Denver Zoo will have to coordinate with the Los Angeles Zoo, because the baby's parents are on loan from California.

Provided by Denver Zoo

Baby giraffe Dobby was born at the Denver Zoo on Feb. 28, 2017.

Kathryn Scott, The Denver Post

New mom, JoRayK, the Denver Zoo's 26-year old female lowland gorilla cuddles her baby born on May 29, 2004. Zoo officials are fairly sure the baby is male, and it is the second endangered gorilla born at the zoo in less than a month.

Glen Martin, The Denver Post

Denver Zoo staff Veterinarian feeding one of the four mongoose babies, Four newbron African Mongoose named the males Rocket, Blitzen and Comet and the female is named Holly, Dec. 16, 2004. The Mongoose babies are being hand- raised by Denver Zoo staff. African banded mongoose newborns are very small, weighing just two ounces and can fit into the palm of a hand. They have just opened their eyes and can be seen being fed by zoo veterinarian staff in the zoo nursery.

Cyrus McCrimmon, The Denver Post

The Denver Zoo held a photo opportunity as the three African lion cubs born September 2004 are starting to venture outside to the main yard of the Predator Ridge exhibit area. The cubs are approximately 35 pounds. One of the baby cubs tugs on the mane of his father 6-year-old Krueger.

Cyrus McCrimmon, The Denver Post

The new baby polar bear cubs, brothers Koda and Nuka, ventured outside into the public exhibit at the Denver Zoo today for their first time in 2005. Their mother Voda was very protective watching the cubs closely as they explored the site. One of the cubs peeks out from between the legs of his mom.

Photo by Dave Parsons, Denver Zoo

In this photo released by the Denver Zoo, a female calf Okapi born at the Denver Zoo in Denver, is shown Thursday, June 23, 2005. Born on June 17, the young female is the third of this species born at the zoo, according to the zoo. Only 21 zoos in North America exhibit the Okapi, and there are only a half-dozen births of this species at these zoos each year, according to the zoo.

Photo provided by Denver Zoo

On August 5, 2005 a baby pale-headed saki monkey was born to mother, Kalei, and father, Naga at Denver Zoo. The infant monkey can be seen clinging to momÕs belly as a mode of transportation around their exhibit in the Emerald Forest building inside Primate Panorama. The baby is very active and can be seen using mom as a jungle gym, running laps around moms torso.

Rebecca McAlpin, Special to The Denver Post

Baby polar bear cubs Ulaq and Berit play in their habitat at the Denver Zoo. The cubs are almost six moths old, their birthday is June 28, 1999 and they recently move to their new location.

Photo by David Parsons, Denver Zoo

Denver Zoo's newest addition is a giant anteater baby named Camilo which means "child born to freedom" in Latin. Camilo was born to parents Monita and Freedom on May 13, 2006.

Photo provided by Denver Zoo

Denver Zoo is celebrating the birth of an endangered eastern bongo antelope that was born on March 30, 2008. Zookeepers named the rambunctious male calf Mkono, which means "handful" in Swahili. Mkono is the fifth calf born to mother, Megan. Mother and calf have been spending time behind the scenes, but can now be seen in their outdoor habitat along with Mkono's older sister, 15-month-old Maddie. David Parsons, Denver Zoo
At Mkono's baby wellness exam, zoo veterinarians gave the new calf a clean bill of health. The young calf weighed in at 45 pounds but when he is full grown, he could weigh up to 900 pounds. Zookeepers say the youngster is very adventurous and is enjoying exploring his new outdoor surroundings under mother's watchful eye.

Matthew Staver, Special to The Denver Post

Two of the three baby Red River Pigs play together at the Denver Zoo Thursday morning. The rare Red River Pigs, Rosie and Rambo had 3 babies 3 weeks ago, named Straw, Sticks, and Bricks . They will grow to be about 100-250 pounds. They were born Sept. 6, 2015. At birth the piglets weighed 2 pounds and were 9inches in length.

Photo provided by Denver Zoo

Sochi, a baby amur leopard, was born at Denver Zoo on Dec. 3, 2013.

Photo provided by Denver Zoo

Blossom, a baby gerenuk, was born to parents Woody and Layla at Denver Zoo on March 6, 2013.

Photo provided by Denver Zoo

A newborn tamandua baby is alive and doing well at Denver Zoo thanks to the dedication of zookeepers and veterinarians that are caring for the infant around the clock. On March 7, 2014 Southern tamandua Rio gave birth to her first offspring, believed to be female, whom keepers have named Cayenne. Unfortunately, Rio left the baby unattended within the first 24 hours and was not allowing her to nurse. Staff stepped in to give supplementary feedings day and night while monitoring the babyÕs condition. They continued to give Rio time to bond with and nurse her baby, and Rio is slowly learning her role as a mother. Little by little, Rio is becoming more accustomed to Cayenne behind-the-scenes at the ZooÕs Gates Animal Housing Center.

Photo provided by Denver Zoo

Denver, CO - Denver Zoo is celebrating the birth of three maned wolf pups, which were born on May 1. The unnamed triplets, made up of two males and one female, were born to mother, Adrianna, and father, Inigo, and are the first of their species to be born at the Zoo since 2009. All three pups were just given a clean bill of health by Denver Zoo veterinarians. Though the pups are not yet old enough to explore the outside world on their own yet, Zoo visitors might catch glimpses of them as their protective mother totes them from den to den inside the Wolf Pack Woods exhibit.

Photo provided by the Denver Zoo

A male sea lion pup was born at the Denver Zoo, 2015.

Photo provided by Denver Zoo

The cubs, a male and a female, were born on the morning of Thursday, September 10, 2015 to lioness Neliah, and are currently with their mother behind the scenes in the Denver Zoo's Benson Predator Ridge exhibit.

Photo provided by the Denver Zoo

Baby otter at the Denver Zoo, 2014.

Photo provided by Denver Zoo

Spotted hyena pup, Kelele at the Denver Zoo, 2014.

Provided by Denver Zoo

Denver Zoo is celebrating its second-ever birth of a southern tamandua, a species of anteater. The new arrival, a male named Salvador, was born on March 12, 2015.

Photo provided by Denver Zoo

A tawny frogmouth chick was born at Denver Zoo on Jan. 27, 2014.

RJ Sangosti, The Denver Post

Rhu, one of two clouded leopard cubs born March 14, at the Denver Zoo, paws at the glass during public viewing hours at the zoo, April 24, 2014. Rhu and her brother Pi are being cared for by Zoo staff around the clock after their mother was unable to take care of them.

Photo provided by Denver Zoo

The number 13 might be a lucky number after all. Denver Zoo is proud to announce the birth of four endangered red ruffed lemurs, the first of their species born here in 13 years! The quadruplets, born March 12, 2011, include male, Rusty and females, Bordeaux, Chianti and Mena. They are now big enough to explore outside their nest box and can be seen with their parents in the Emerald Forest exhibit in Denver Zoo's Primate Panorama.

Photo by Dave Parsons, Denver Zoo

Aloha! Denver Zoo is celebrating the hatching of three nene (nay nay), or Hawaiian, geese. Two hatched May 7 and the third hatched May 9, 2011. These goslings are the first to hatch in several years at Denver Zoo. Though the three female goslings will eventually be on display, they are currently growing and developing under the watchful eye of bird keepers in the zoo's Bird Propagation Center.

Photo provided by Denver Zoo

Denver Zoo hatched a Crocodile monitor (Varanus salvadorii) on January 9, 2003 after a 201-day incubation period. This is the first hatching at the Denver Zoo and only the sixth successful hatching of this species in a U.S. zoo.

Cyrus McCrimmon, The Denver Post

A 5-week-old spotted hyena cub named Isoke made it's media and public debut in 2005 with it's mother Ngozi at the Denver Zoo. They were in the maternity den of Predator Ridge. Born completely brown, the cub will develop spots on it's coat. Zookeepers have not identified the sex of the cub yet.

Photo by Dave Parsons, Denver Zoo

Denver Zoo is hand raising a rare 10-day old female golden-cheeked gibbon (Hylobates gabriellae) named Lily in 2005. She is doing well under the careful watch of zookeepers.

Photo provided by Denver Zoo

Kazi, a female African lion cub born at the Denver Zoo on Oct. 25, 2006.

Photo provided by Denver Zoo

Denver Zoo welcomes two new arrivals, spotted hyena cubs (Crocuta crocuta) born to mother, Ngozi (Nuh-Go-Zee) and father, Kibo (Kee-boe) on November 14, 2006. The cubs will go on exhibit sometime this spring. However, visitors can see mother and cubs via a live video feed on monitors in the interpretive center of Predator Ridge. There are only 51 spotted hyenas on exhibit in 19 North American zoos. The hyena cubs weighed less than three pounds at birth and are growing fast, now each weighing about five pounds! Zookeepers have identified the sex of the newborns as a male and female, but they have not yet been given names. This is the third hyena birth in Predator Ridge in since March of 2005 when the first cub was born at Denver Zoo since 1987. The hyenas share the use of the habitat with African Wild dogs and lions on a rotational basis. Like the other animals in Predator Ridge, spotted hyenas are native to Africa. Hyenas are mostly found south of the Sahara Desert, excluding the southern tip of Africa and the Congo Basin. The spotted hyena is the largest of the four hyena species and can grow up to four feet tall and weigh up to 250 pounds. These hyenas have longer forelegs than hind legs and feature sandy brown spotted coats. Spotted hyenas scavenge carcasses or kill prey in packs. These packs can bring down large prey like zebras and can force lions to abandon a kill. A single hyena is capable of chasing and killing prey three times its own weight. The spotted hyena has very powerful jaws that can even crunch through large bones resulting in white excrement.

Photo provided by Denver Zoo

A Red-capped mangabey monkey named Kanzu was born at the Denver Zoo on Sept. 30, 2007.

Photo provided by Denver Zoo

The Denver Zoo Polar Bear Cubs " Boris and Natasha " make their Public Debut. After a winter of feeding on moms rich milk , denver zoo polar bear cubs, thriving under the care of their mother Voda, emerged from their denning area . The cubs , Boris ( male ) and Natasha (female were born to Voda ( female )and kavek ( male ), on November 15, 1999 . The twin cubs can be told apart by their size, Boris is slightly bigger than Natasha . The cubs with some help from their mother enter the Northern Shores exhibit for the first time . Photo is of Denver Zoo Twin Polar Bears,Natasha and (Boris standing looking though a window at the Media ) with their mother Voda in ( background )at the Northern Shores exhibit .

Photo provided by Denver Zoo

Denver Zoo's spotted hyenas (Crocuta crocuta) born on March 3, 2015 are now regularly on exhibit outside. Visitors can watch the cubs, named Kidogo (Kid-oh-goh) and Kubwa (Koob-wah) through their stages of development at Predator Ridge. Zookeepers gave the cubs Swahili names.

RJ Sangosti, The Denver Post

The Denver Zoo welcomed its newest resident, a newborn colobus monkey named Darby. The infant, whose gender is still unknown, is being held by his mother Sadie, 2008.

Photo by Dave Parsons, Denver Zoo

Endanered Golden Lion Tamarin born at the Denver Zoo in 2009. Mother "Rosie" carries the newborn who has yet to be named until sex can be determined.

Photo by Dave Parsons, Denver Zoo

A zoo hospital staff member examining a newborn aye-aye, a rare endangered primate found in Madagascar, that was born at the zoo on April 18, 2009. The infant's birth is significant as it is only the second aye-aye to be born at a North American zoo as well as the first to be conceived at a North American zoo.

Photo by Dave Parsons, Denver Zoo

Denver Zoo is celebrating the birth of a rare okapi (Oh-kah-pee). The female calf, named Kalispell (Kal-i-spell), was born to mother, Iosi (Ee-oh-see), and father, Jekaro (Jeh-car-oh), on June 27, 2009 and is only the fifth birth of this species at the zoo. Kalispell will remain behind the scenes for a short while longer, but visitors will soon be able to see the youngster as she grows and becomes more self-sufficient.

Denver Zoo is thrilled to announce the birth of a De Brazza's Monkey named Kanani! She was born to mother, Marinda and father, Kisoro, on December 19, 2009. Kanani is described as very active and playful despite MarindaÕs attempts to be protective. Weather permitting, visitors can see her wiggle away from her mom in Primate Panorama.

Photo provided by Denver Zoo

Baby giraffe at the Denver Zoo, born April 14, 2010, named Cricket.

Photo provided by Dave Parsons, Denver Zoo

Denver Zoo Sumatran orangutan, Hesty (Hess-tee), will make her public debut Aug. 2, 2010. Hesty, the first birth of her species at the zoo in 25 years, is doing fine now with her mother. This is after a rocky start to the infantÕs life and two months behind-the-scenes receiving care from zookeepers and veterinary staff. Beginning August 21, visitors will be able to see them both between 10 a.m. and 3 p.m. in the Great Apes Building most days. Animal care needs may alter this schedule, however.

Photo by Dave Parsons, Denver Zoo

Denver Zoo's four endangered, Amur tiger cubs took a breath of fresh air Monday as they explored their outdoor habitat for the first time. The cubs - females Zaria and Akasha and males Nikolai and Thimbu - were each given a clean bill of health in their last exams and are ready to meet the public. The quadruplet cubs, born May 31, 2010 are the first of their species to be born at Denver Zoo since 2003. Just in time for Labor Day, visitors can see the foursome now at the Feline II Building.

Dave Parsons, Denver Zoo

Denver Zoo is thrilled to announce the birth of a male De Brazza's Monkey named Kanoa! He was born to mother, Marinda and father, Kisoro, on Nov. 27, 2011. This is the second birth for Kisoro, who came to Denver Zoo under extraordinary circumstances. Weather permitting, visitors can see Kanoa climbing around his habitat in Primate Panorama.

Dave Parsons, Denver Zoo

Denver Zoo recently welcomed two palm cockatoos from two different breeding pairs. The chicks hatched on January 18 and February 10, 2011 and their genders are still unknown. Though the hatchlings will eventually be on display at the zoo's Nurture Trail exhibit, they are currently growing and developing under the watchful eye of bird keepers in the zoo's Bird Propagation Center.
Palm cockatoos are unique among other cockatoos for their dark-gray or black feathers, which cover most of their bodies, with the exception of red patches on their cheeks. They are about two-feet-long and have developed large, very strong beaks which allow them to crack open and eat extremely hard nuts.

Photo courtesy of Denver Zoo

The Denver Zoo announced the birth and public debut of Penny, a red ruffed lemur, on Thursday, May 18, 2017. She was born at the zoo to mother Sixpence and father Mego on April 25, 2017.

Provided by Denver Zoo

Denver Zoo is celebrating the birth of three maned wolf pups, which were born on May 1. The unnamed triplets, made up of two males and one female, were born to mother, Adrianna, and father, Inigo, and are the first of their species to be born at the Zoo since 2009.

Zoo officials hope to tackle these issues with their revised master plan, which includes a $20 million, state-of-the-art animal hospital scheduled to break ground later this year, supported by $10 million from the $937 million General Obligation Bond Denver that voters passed last year.

The zoo last month also received city approval for admission-fee hikes — $2 to $3 per visitor — to cover operational costs that have risen 28 percent over the past four years. The higher fees are projected to raise $1.5 million in the next year, boosting the zoo’s $41.5 million annual budget by 3.7 percent.

“We’ve got a lot of things like this around the campus that are in need of updating,” said Brian Aucone, senior vice president for animal sciences, as he stood outside the 84-acre zoo’s current hospital, a squat cinderblock structure built in 1969.

At 23,000 square feet, the new hospital will more than double its size and allow visitors to actually see the animals being cared for.

“We requested $70 million from the (GO Bond),” O’Malley said, “and we got $20 million. We’re grateful for it, and we’re not looking to do everything at once, but we did need to revise our master plan as a result.”

Adaptation is vital for a complex organism such as the Denver Zoo. Zoos and aquariums have evolved from the live-animal galleries of yore to wildlife conservation and education centers — led, at times, by the Denver Zoo’s innovative exhibits.

Those include the oft-copied “rotational” habitat of Predator Ridge (opened in 2004), Toyota Elephant Passage (2012) and the up-close-and-personal tiger exhibit, The Edge (2017), which instantly doubled the tigers’ outdoor space and allows the animals to prowl 12 feet above visitors’ heads on bridges.

Of the roughly 2,300 zoos regulated by the U.S. Department of Agriculture, only 10 percent have been accredited through the Association of Zoos & Aquariums, the Silver Spring, Md.-based body that since 1976 has set standards for the biggest municipal zoos and aquariums in the nation. Most of the 2,300 are “roadside zoos,” according to Aucone.

Not Denver’s.

“They were right there at the start when we first started accrediting institutions, and they’ve been consistently there ever since,” said AZA spokesman Rob Vernon. “That alone puts them in rarefied air, but they’ve always been ahead of the curve in conservation.”

The Denver Zoo has sent staff, funding or both to more than 600 wildlife conservation projects since 1996, according to spokesman Jake Kubie. Among its 350 employees and nearly 700 volunteers, the zoo employs a 14-member Field Conservation team to support the $2.2 million it spends on protecting wildlife annually around the globe.

Roughly $20 million, or half of the zoo’s annual budget, goes toward care for animals, from Instagram-ready baby giraffes and orangutans to free-roaming peacocks and insects. Some of that comes from taxpayers in the seven-county Scientific & Cultural Facilities District, a special tax district that last year gave the zoo $9.1 million.

“The Denver Zoo plays in the national arena,” SCFD executive director Deborah Jordy said. “They’ve really stepped up to being a leader in conservation. And having a healthy and vibrant zoo is critical to our arts, science and culture ecosystem.”

Unlike other Tier 1 SCFD organizations — such as the Denver Art Museum — the zoo relies less on changing exhibits and more on the perennial appeal of seeing exotic and wild animals with one’s own eyes.

“I have pictures of myself at 3 years old in front of the giraffes here,” Aucone said. “You can’t get that smell, that feeling, in a book or in virtual reality.”

Despite the Denver Zoo’s built-in family audience, the attraction’s reputation has been challenged in recent years. In general, animal rights activists have highlighted the dangers of keeping animals in captivity, while the zoo has had its own woes with the city.

In September 2015, zoo officials dropped plans for a biomass gasification system that they planned to use to convert animal waste into energy. Neighbors had fought the proposal, raising questions about its safety and the potential for odors from what they described as an incinerator in the middle of City Park.

Zoo officials said the decision was largely about money and the difficulty of adapting untested technology. But the abandoned plan raised issues between the zoo and the Denver Auditor’s Office. In April 2016, Auditor Tim O’Brien said officials had been stonewalling his efforts to audit the zoo, which he had been pursuing for months.

When the long-awaited city audit arrived in January 2017, it revealed that the abandoned waste-conversion plan cost the zoo $3.5 million. The zoo eventually took a $1.7 million write-off on its accounting records.

Significantly, the audit, which was the zoo’s first, didn’t find any major demerits. And as recently as last week, city auditor O’Brien’s follow-up report praised the zoo’s embrace of all of the city’s recommendations, including updates to a cooperative agreement that holds the zoo more accountable with accreditation and other standards.

But since Block departed in June 2017, neither she nor the zoo has explained why or whether she quit or was forced out.

“Ultimately, the zoo is responsible to the public,” Block, now the CEO of the volunteer-focused World Forward Foundation, wrote via email from Australia last week. “The taxpayers make the zoo possible. The public defines the zoo’s value.”

Whoever is chosen as the new CEO — final applications were due Friday — will oversee deferred maintenance on the aquatic Northern Shores area, as well as a board that’s being split into operations and finance (the new Board of Governors) and a Leadership Council, which will spearhead fundraising.

“We’ve got 68,000 household memberships,” O’Malley said. “We’re proud of that. But our priority is taking care of our animals and maximizing guest engagement so that they feel they’re a part of this — beyond just walking through and being an observer.”

John Wenzel has covered comedy, music, film, books and video games for The Denver Post for more than a decade. As a proud Dayton, Ohio native, his love of Guided by Voices is about equal to his other obsessions, including Peter Jackson's Middle-earth, "Mr. Show" quotes and Onitsuka Tigers.

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